Air-brake-regulating apparatus



(No Model.)

H. E. HUNT. AIR BRAKE RBGULATING APPARATUS.

No. 529,270. Patented Nov. 13, 1894 WITNESSES INVENTOR UNITED STATES PATENT rrrcn.

' HERBERT E. HUNT, OF PITTSBURG, PENNSYLVANIA.

AlR-BRAKE-REGULATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 529,270, dated November 13, 1894.

Application filed May 2, 1894. Serial No. 509,775. (No model.)

T0 at whom it may concern.-

Be it known that l, HERBERT E. HUNT, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Air-Brake-Regulating Apparatus, of which the following is a full, clear, and exact description, reference be ing had to the accompanying drawing, forming part of this specification, which shows in elevation, partly in section, apparatus constructed in accordance with my invention.

My improvement is designed to form part of an air-brake system for cars, in which the air reservoir is supplied by a pump adapted to be constantly operated during the motion of the car, by connection withbne of the moving parts of the latter. It is principally intended for use upon street railway cars, and its object is to economize power and to save wear upon the pump, by providing automatic means whereby when a proper degree of airpressure is attained in the reservoir, the connection of the pump therewith is throttled or cut off, and a connection is established between the pump and the atmosphere so that the pump may then operate without substantial back pressure or resistance. The advantages gained by this improvement are very material and will be appreciated by those skilled in the art.

In the drawing, 2 represents the air reservoir for supplying air to the brake cylinder. It is connected by a pipe 3 with the air pump, (not shown) which is driven constantly during motion of the car by connection with the axle or other moving part of the traction or electric motor car to which the apparatus is applied.

4. is a check-valve interposed in the pipe 3, and adapted to permit the air to be forced from the pump into the reservoir and to prevent its back flow.

5 is a regulating valve chamber having ports 6, and 7, one communicating by a pipe 8 with the pump by way of the pipe 3, and the other, a by-port, opening directly or through an exhaust pipe 9 into the atmosphere.

10 is a valve of inverted conical shape which fits a similarly shaped seat in the partition or plate 11 fixed within the chamber, and 12 is the stem of the valve which at its lower end abuts against the upper face of a piston 13 contained within a chamber 14, which preferably forms an enlarged portion of the chamher 5 and communicates with the air reservoir by a pipe 15. Upon the upper face ofthe valve rests a boss 16 projecting from the under face of a triangular or other irregularly shaped plate or guide 17, which is pressed downwardly by a spiral spring 18. A disk 19 rests upon the spring inside the upper cylinderhead, and the tension of the spring is regulated by the screw spindle 20, which passes through the head and abuts against the disk 19, this spindle having a squared upper end for the application of a wrench.

The operation of the apparatus is as follows: Suppose the air in the reservoir 2 to be at atmospheric pressure, and the car to be starting. The valve 10 is in such case held down by the spring 18 so that communication between the ports 6 and 7, is closed, and as the pump is operated the air compressed thereby will pass through the pipe 3 and check-valve 4 to the reservoir. When the air pressure in the latter has become sufliciently high to exert upon the piston 13 and valve 10 a force greater than the resistance olfered by the spring, the valve will be lifted from its seat so as to open communication between the ports 6 and 7, and thereupon the air compressed by the pump will pass freely through the pipe 8, and ports 6 and 7 to the atmosphere, and the work of compression will be relieved immediately from the pump. When the air in the reservoir is reduced below the point necessary to move the valve against the spring, the valve will be forced into the position shown in the drawing, thus shutting off connection of the exhaust port with the pump, and causing the pump to discharge into the reservoir. By means of the adjusting mechanism of the Valve, the tension of the spring may be regulated so as to maintain any desired degree of pressure within the reservoir.

\Vithin the scope of my invention, modifications in the form, construction and relative arrangement of the parts may be made by the skilled mechanic. Thus adiaphragm may replace the piston and valve-regulating mechanism, or valves of other kinds may be substituted for those shown in the drawing.

1 claim- 1. In air-brake apparatus, the combination of a constantly operated pump, an air-reservoir connected therewith, a regulating valve adapted to connect'the pump with a by-port, communicating with the atmosphere and means whereby said valve is operated automatically by the pressure of air in the reservoir; substantially as described.

2. In air-brake apparatus, the combination of a constantly operated pump, an air-reservoir connected therewith, a regulating valve adapted to connect the pump with a by-port, communicating with the atmosphere means whereby said valve is operated automatically by the pressure of air in the reservoir, and a check-valve between the pump and reservoir; substantially as described.

3. In air-brake apparatus, the combination HERBERT E. HUNT.

Witnesses:

W. B. CORWIN, H. M. UORWIN. 

